解9x²-49=09x²=49x²=49/9x=7/3或x=-7/336-x²=0x²=36x=6或x=-6(x+3)²-36=0(x+3-6)(x+3+6)=0(x-3)(x+9)=0∴x=3或x=-99(1-2x)²-16=0[3(1-2x)-4][3(1-2x)+4]=0(-6x-1)(-6x+7)=0∴x=-1/6或x=7/6
